Loading and transporting sensitive electronic equipment has presented numerous problems. Typically, such equipment is packed in a suitable shipping container. Even slight impacts or vibrations to the container, however, produce shock forces that may damage precision instruments if they are not properly supported within the container.
To adequately protect electronic equipment, it is well known to use heavy-duty containers molded from polyethylene for high impact strength. An example of this type of shipping container is disclosed in U.S. Pat. No. 4,284,202, issued Aug. 8, 1981, to Barstow, Jr. It is also necessary to build into these rugged containers a shock-mitigation system that is capable of protecting the equipment from possible damage during shipping and other rough handling. One known system employs a mounting rack constructed from a plurality of welded vertical and horizontal frame members and shock mounts designed to hold the electronic equipment stationary and to absorb shocks.
The problem with that prior art electronic rack mounting frames is that the vertical and horizontal members are Gas Shielded Tungsten Arc (TIG) welded together to form an integral frame structure. Although the welded rack frame is sufficiently strong to withstand most impacts and transmit the shock forces produced thereby from the shock mounts to the electronic equipment without damage, there are difficulties associated with its construction.
First and foremost is the time required to weld the various frame members together and to correct any distortions caused during the welding process, which adds considerably to the cost of manufacturing the mounting rack. Because of imprecisions in the welding process, it is difficult to maintain alignment of the mounting holes which are used to secure the electronic equipment modules to the rack. A further disadvantage of a welded rack system is the storage space required to keep finished racks in stock in order to fill orders promptly.